I was going through some of the older threads and found this. You've probably already figured this all out yourself, but if not, here are some answers:
1.Could you help me finding wich is the sata max speed i can have with my pc?
Your mobo supports SATA II at 3 Gbits/sec. SATA III drives are backwards compatible with your board, but you won't get SATA III speeds (6Gbits/sec).
2. Also what other parameter do I have to look at to see where is my bottleneck(or what component will limit my pc speed.
Short of buying a new mobo and CPU, adding an SSD will certainly speed things up. Other than that, all you can really do is optimize your software settings.
3 finally is it worth it to buy a ssd im my case considering the limits of my system?
If you're not planning on upgrading you CPU and mobo, then adding an SSD is probably the single best way of improving your system speeds. Your OS launch time and file retrieval/transfer times will all be radically reduced. You can still use your HDD, just shift it to storage rather than using it as a boot drive.
4 Is it necessary to check my bios version , if yes how to? No, but you should keep your BIOS up to date.
5 I dont remeber if ssd plugs in pci too whats faster pci or sata on the mobo -
You can get PCIe SATA which is faster, but there's not really any point unless you're setting up a server. For normal use, the speed difference between PCIe and SATA isn't worth the cost.
Hope this helps! Cheers.